International System Safety Society Congress 2015 A Model-Based Safety and Dependability Methodology for Missile Safety Engineering

摘要

Model-based methods are becoming more prevalent to support system development processes while in the field of Safety and Dependability (S&D) this adoption is slower. This contribution reports about model based S&D engineering along the V-model from concept to operation phase in an industrial application. In the concept phase, the design engineer has the complex task to find an architecture fulfilling safety, reliability, availability and testability targets. We propose a qualitative modeling approach in which, during the early stage of design, models can be quickly built to support the full range of S&D analyses such as: computation of cause-effect relationships, automatic generation of FTAs, automatic generation of RBDs, system availability prediction or systematic evaluation of the Diagnostic Coverage. At this stage, the qualitative model supports the system and subsystem specifications’ validation process and provides a systematic framework to reduce the risk of not meeting the RAMST targets. Later in the development cycle a full quantitative model is built (semi-automatically from importing the ECAD-net lists) using component model libraries. While maintaining drawing set consistency of analysis results, this final model quickly unveils the safety impacts of design changes, enables automated computation of even double-fault FMECAs and supports model-based diagnostics during operation of the system.